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authorAleksey Kladov <[email protected]>2018-08-10 20:33:29 +0100
committerAleksey Kladov <[email protected]>2018-08-10 20:33:29 +0100
commit7c67612b8a894187fa3b64725531a5459f9211bf (patch)
tree9e2a536efa0c880d921fd8d4d74423afc9451fd4 /src/grammar/expressions/mod.rs
parent26262aaf05983c5b7f41cc438e287523268fe1eb (diff)
organizize
Diffstat (limited to 'src/grammar/expressions/mod.rs')
-rw-r--r--src/grammar/expressions/mod.rs379
1 files changed, 0 insertions, 379 deletions
diff --git a/src/grammar/expressions/mod.rs b/src/grammar/expressions/mod.rs
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index dcbb1e2a8..000000000
--- a/src/grammar/expressions/mod.rs
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@@ -1,379 +0,0 @@
1mod atom;
2
3use super::*;
4pub(super) use self::atom::literal;
5
6const EXPR_FIRST: TokenSet = LHS_FIRST;
7
8pub(super) fn expr(p: &mut Parser) -> BlockLike {
9 let r = Restrictions { forbid_structs: false, prefer_stmt: false };
10 expr_bp(p, r, 1)
11}
12
13pub(super) fn expr_stmt(p: &mut Parser) -> BlockLike {
14 let r = Restrictions { forbid_structs: false, prefer_stmt: true };
15 expr_bp(p, r, 1)
16}
17
18fn expr_no_struct(p: &mut Parser) {
19 let r = Restrictions { forbid_structs: true, prefer_stmt: false };
20 expr_bp(p, r, 1);
21}
22
23// test block
24// fn a() {}
25// fn b() { let _ = 1; }
26// fn c() { 1; 2; }
27// fn d() { 1; 2 }
28pub(super) fn block(p: &mut Parser) {
29 if !p.at(L_CURLY) {
30 p.error("expected block");
31 return;
32 }
33 atom::block_expr(p);
34}
35
36#[derive(Clone, Copy)]
37struct Restrictions {
38 forbid_structs: bool,
39 prefer_stmt: bool,
40}
41
42enum Op {
43 Simple,
44 Composite(SyntaxKind, u8),
45}
46
47fn current_op(p: &Parser) -> (u8, Op) {
48 if p.at_compound2(PLUS, EQ) {
49 return (1, Op::Composite(PLUSEQ, 2));
50 }
51 if p.at_compound2(MINUS, EQ) {
52 return (1, Op::Composite(MINUSEQ, 2));
53 }
54 if p.at_compound3(L_ANGLE, L_ANGLE, EQ) {
55 return (1, Op::Composite(SHLEQ, 3));
56 }
57 if p.at_compound3(R_ANGLE, R_ANGLE, EQ) {
58 return (1, Op::Composite(SHREQ, 3));
59 }
60 if p.at_compound2(PIPE, PIPE) {
61 return (3, Op::Composite(PIPEPIPE, 2));
62 }
63 if p.at_compound2(AMP, AMP) {
64 return (4, Op::Composite(AMPAMP, 2));
65 }
66 if p.at_compound2(L_ANGLE, EQ) {
67 return (5, Op::Composite(LTEQ, 2));
68 }
69 if p.at_compound2(R_ANGLE, EQ) {
70 return (5, Op::Composite(GTEQ, 2));
71 }
72 if p.at_compound2(L_ANGLE, L_ANGLE) {
73 return (9, Op::Composite(SHL, 2));
74 }
75 if p.at_compound2(R_ANGLE, R_ANGLE) {
76 return (9, Op::Composite(SHR, 2));
77 }
78
79 let bp = match p.current() {
80 EQ => 1,
81 DOTDOT => 2,
82 EQEQ | NEQ | L_ANGLE | R_ANGLE => 5,
83 PIPE => 6,
84 CARET => 7,
85 AMP => 8,
86 MINUS | PLUS => 10,
87 STAR | SLASH | PERCENT => 11,
88 _ => 0,
89 };
90 (bp, Op::Simple)
91}
92
93// Parses expression with binding power of at least bp.
94fn expr_bp(p: &mut Parser, r: Restrictions, bp: u8) -> BlockLike {
95 let mut lhs = match lhs(p, r) {
96 Some(lhs) => {
97 // test stmt_bin_expr_ambiguity
98 // fn foo() {
99 // let _ = {1} & 2;
100 // {1} &2;
101 // }
102 if r.prefer_stmt && is_block(lhs.kind()) {
103 return BlockLike::Block;
104 }
105 lhs
106 }
107 None => return BlockLike::NotBlock,
108 };
109
110 loop {
111 let is_range = p.current() == DOTDOT;
112 let (op_bp, op) = current_op(p);
113 if op_bp < bp {
114 break;
115 }
116 let m = lhs.precede(p);
117 match op {
118 Op::Simple => p.bump(),
119 Op::Composite(kind, n) => {
120 p.bump_compound(kind, n);
121 }
122 }
123 expr_bp(p, r, op_bp + 1);
124 lhs = m.complete(p, if is_range { RANGE_EXPR } else { BIN_EXPR });
125 }
126 BlockLike::NotBlock
127}
128
129// test no_semi_after_block
130// fn foo() {
131// if true {}
132// loop {}
133// match () {}
134// while true {}
135// for _ in () {}
136// {}
137// {}
138// }
139fn is_block(kind: SyntaxKind) -> bool {
140 match kind {
141 IF_EXPR | WHILE_EXPR | FOR_EXPR | LOOP_EXPR | MATCH_EXPR | BLOCK_EXPR => true,
142 _ => false,
143 }
144}
145
146const LHS_FIRST: TokenSet =
147 token_set_union![
148 token_set![AMP, STAR, EXCL, DOTDOT, MINUS],
149 atom::ATOM_EXPR_FIRST,
150 ];
151
152fn lhs(p: &mut Parser, r: Restrictions) -> Option<CompletedMarker> {
153 let m;
154 let kind = match p.current() {
155 // test ref_expr
156 // fn foo() {
157 // let _ = &1;
158 // let _ = &mut &f();
159 // }
160 AMP => {
161 m = p.start();
162 p.bump();
163 p.eat(MUT_KW);
164 REF_EXPR
165 }
166 // test unary_expr
167 // fn foo() {
168 // **&1;
169 // !!true;
170 // --1;
171 // }
172 STAR | EXCL | MINUS => {
173 m = p.start();
174 p.bump();
175 PREFIX_EXPR
176 }
177 DOTDOT => {
178 m = p.start();
179 p.bump();
180 expr_bp(p, r, 2);
181 return Some(m.complete(p, RANGE_EXPR));
182 }
183 _ => {
184 let lhs = atom::atom_expr(p, r)?;
185 return Some(postfix_expr(p, r, lhs));
186 }
187 };
188 expr_bp(p, r, 255);
189 Some(m.complete(p, kind))
190}
191
192fn postfix_expr(p: &mut Parser, r: Restrictions, mut lhs: CompletedMarker) -> CompletedMarker {
193 let mut allow_calls = !r.prefer_stmt || !is_block(lhs.kind());
194 loop {
195 lhs = match p.current() {
196 // test stmt_postfix_expr_ambiguity
197 // fn foo() {
198 // match () {
199 // _ => {}
200 // () => {}
201 // [] => {}
202 // }
203 // }
204 L_PAREN if allow_calls => call_expr(p, lhs),
205 L_BRACK if allow_calls => index_expr(p, lhs),
206 DOT if p.nth(1) == IDENT => if p.nth(2) == L_PAREN || p.nth(2) == COLONCOLON {
207 method_call_expr(p, lhs)
208 } else {
209 field_expr(p, lhs)
210 },
211 DOT if p.nth(1) == INT_NUMBER => field_expr(p, lhs),
212 // test postfix_range
213 // fn foo() { let x = 1..; }
214 DOTDOT if !EXPR_FIRST.contains(p.nth(1)) => {
215 let m = lhs.precede(p);
216 p.bump();
217 m.complete(p, RANGE_EXPR)
218 }
219 QUESTION => try_expr(p, lhs),
220 AS_KW => cast_expr(p, lhs),
221 _ => break,
222 };
223 allow_calls = true
224 }
225 lhs
226}
227
228// test call_expr
229// fn foo() {
230// let _ = f();
231// let _ = f()(1)(1, 2,);
232// }
233fn call_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
234 assert!(p.at(L_PAREN));
235 let m = lhs.precede(p);
236 arg_list(p);
237 m.complete(p, CALL_EXPR)
238}
239
240// test index_expr
241// fn foo() {
242// x[1][2];
243// }
244fn index_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
245 assert!(p.at(L_BRACK));
246 let m = lhs.precede(p);
247 p.bump();
248 expr(p);
249 p.expect(R_BRACK);
250 m.complete(p, INDEX_EXPR)
251}
252
253// test method_call_expr
254// fn foo() {
255// x.foo();
256// y.bar::<T>(1, 2,);
257// }
258fn method_call_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
259 assert!(
260 p.at(DOT) && p.nth(1) == IDENT
261 && (p.nth(2) == L_PAREN || p.nth(2) == COLONCOLON)
262 );
263 let m = lhs.precede(p);
264 p.bump();
265 name_ref(p);
266 type_args::type_arg_list(p, true);
267 arg_list(p);
268 m.complete(p, METHOD_CALL_EXPR)
269}
270
271// test field_expr
272// fn foo() {
273// x.foo;
274// x.0.bar;
275// }
276fn field_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
277 assert!(p.at(DOT) && (p.nth(1) == IDENT || p.nth(1) == INT_NUMBER));
278 let m = lhs.precede(p);
279 p.bump();
280 if p.at(IDENT) {
281 name_ref(p)
282 } else {
283 p.bump()
284 }
285 m.complete(p, FIELD_EXPR)
286}
287
288// test try_expr
289// fn foo() {
290// x?;
291// }
292fn try_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
293 assert!(p.at(QUESTION));
294 let m = lhs.precede(p);
295 p.bump();
296 m.complete(p, TRY_EXPR)
297}
298
299// test cast_expr
300// fn foo() {
301// 82 as i32;
302// }
303fn cast_expr(p: &mut Parser, lhs: CompletedMarker) -> CompletedMarker {
304 assert!(p.at(AS_KW));
305 let m = lhs.precede(p);
306 p.bump();
307 types::type_(p);
308 m.complete(p, CAST_EXPR)
309}
310
311fn arg_list(p: &mut Parser) {
312 assert!(p.at(L_PAREN));
313 let m = p.start();
314 p.bump();
315 while !p.at(R_PAREN) && !p.at(EOF) {
316 expr(p);
317 if !p.at(R_PAREN) && !p.expect(COMMA) {
318 break;
319 }
320 }
321 p.eat(R_PAREN);
322 m.complete(p, ARG_LIST);
323}
324
325// test path_expr
326// fn foo() {
327// let _ = a;
328// let _ = a::b;
329// let _ = ::a::<b>;
330// let _ = format!();
331// }
332fn path_expr(p: &mut Parser, r: Restrictions) -> CompletedMarker {
333 assert!(paths::is_path_start(p));
334 let m = p.start();
335 paths::expr_path(p);
336 match p.current() {
337 L_CURLY if !r.forbid_structs => {
338 struct_lit(p);
339 m.complete(p, STRUCT_LIT)
340 }
341 EXCL => {
342 items::macro_call_after_excl(p);
343 m.complete(p, MACRO_CALL)
344 }
345 _ => m.complete(p, PATH_EXPR)
346 }
347}
348
349// test struct_lit
350// fn foo() {
351// S {};
352// S { x, y: 32, };
353// S { x, y: 32, ..Default::default() };
354// }
355fn struct_lit(p: &mut Parser) {
356 assert!(p.at(L_CURLY));
357 p.bump();
358 while !p.at(EOF) && !p.at(R_CURLY) {
359 match p.current() {
360 IDENT => {
361 let m = p.start();
362 name_ref(p);
363 if p.eat(COLON) {
364 expr(p);
365 }
366 m.complete(p, STRUCT_LIT_FIELD);
367 }
368 DOTDOT => {
369 p.bump();
370 expr(p);
371 }
372 _ => p.err_and_bump("expected identifier"),
373 }
374 if !p.at(R_CURLY) {
375 p.expect(COMMA);
376 }
377 }
378 p.expect(R_CURLY);
379}
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